1. Field of the Invention
The present invention concerns an apparatus for manually portioning pizza dough disks of measured volume and suitable for mechanical final spreading of the pizza dough, in particular under the influence of the centrifugal force, in which the dough, previously subdivided into portions of a volume greater than the one of the calibrated dough disk, is pressed between two flat surfaces of circular shape.
The present invention also concerns a method of operating the portioning apparatus.
2. Discussion of Background Information
In the trade of manually manufacturing pizzas where the dough discs are prepared one by one by an operator more or less trained for this task this operation inevitably involves the forming of a ball of prepared dough of predetermined weight (of about 200 g) which ball then is spread out to form a thin disk of dough of the desired volume. If the formation of the dough disk is effected entirely manually, preferably by an experienced pizzaiolo who spreads the dough into its final shape by swirling it in the air overhead, the forming of the initial dough ball presents no particular problems concerning the consistency of its weight (or of its volume which in a homogeneous and well raised dough perfectly correlates with its weight). In this case the pizzaiolo as a rule can rely on his expert ability using which he is able to subdivide the dough into balls (or blocks) of fairly constant weight ranging within acceptable tolerances as well as to correct any small errors in his weight judgement during the subsequent step of spreading the dough. If the pizzaiolo notices he formed a ball of excessive weight he just "spreads" the dough applying a little less energy (and centrifugal force in the last operation connected to the swirling of the dough disk in the air) for obtaining the desired disk diameter all the same. The only difference compared to the ideal spreading of the dough is that the disk of dough is somewhat thicker which the expert pizzaiolo easily can take into account during the baking process. The opposite deviation, if a dough ball turns out to be too light, is corrected by spreading it more intensely for obtaining a dough disk the same diameter desired, which just is a bit thinner. All this requires the work of an expert pizzaiolo who performs all operations manually himself and thus is in a position to take corrective action against any deviations throughout the production process.
In recent times, a consistent evolution is noticed in the craft of pizza preparation which is speeded up considerably since the introduction of mechanical systems which spread the dough disk using devices applying--exactly as the traditional pizzaiolo does--centrifugal force. These machines are able to spread the dough, starting from a dough disk of about 18 cm, to its final diameter of the pizza disk of about 35 or 40 cm as desired very fast and reliably. Their advantage is seen in the speed of the operation (a plurality of dough disks is spread out in just a few seconds) and mainly in that the specific manual dexterity of a professional pizzaiolo can be dispensed with. Any person, even without particular training thus is capable of spreading a perfect pizza disk of constant diameter and consistent properties, which constitutes a considerable advantage for small and medium pizzeria operations which not always can afford to hire an experienced pizzaiolo. Such pizza spreader machines, especially if a plurality of dough disks is processed simultaneously (i.e. if more than one dough disk is spread out in one go), for correct operation and for producing pizza disks all of the same diameter, must be supplied, however, with dough disks (seen as an intermediate product in the production process) of calibrated weight ranging within quite stringent tolerance limits. The pizza spreader machine itself is not able to distinguish too heavy dough disks from too light ones, and especially if a plurality of disks are to be spread in the same operation, the same centrifugal force is applied to all of them in such a manner that different pizza disk diameters would result. This obviously is not a sound base of a pizzeria operation.
According to the state of the art dough portioning devices are already known, in particular for manufacturing bread or similar products, but they mostly concern actual machines not operated manually and laid out for producing great daily quantities of bread loafs or rolls, etc. Such machines, the main objective of which is to accelerate the production of bread dough balls without subjecting the dough to excessive mechanical or thermal strain--strain that would impair the quality of the final product--in many cases function according to the principle of a cylinder into which the dough is sucked in and from which it then is expulsed using a piston. Such machines require a source of suction vacuum for sucking in the dough. Such machines, the disadvantage of which for small and medium pizzeria operations is seen in the necessity of installing a suction plant for sucking in the dough, which results in an installation which is too complex and cost-intensive, are known e.g., from the CH-583520, CH-490805, CH-604531and CH-609212 as well as from the U.S. Pat. No 5,269,674.
Other types also known of dough subdividing or portioning devices are not adapted to craft trade pizzerias at which type operation the present invention is aimed at in particular: thus the DE-3826934 which shows a dough subdividing device functioning with two measuring chambers arranged on a metering cylinder and equipped with pistons ejecting the portion of dough, or the DE-3444085 in which a system is shown for portioning the dough, working with a pair of rolls provided with chambers which are open in the radial direction, and the points of which meet in a common plane, and which thus subdivide the dough into portions, an arrangement which shows solutions of mechanical problems which are quite complex and suitable for manufacturing great quantities of units per hour, which are usual in today's industrial bread plants.
Manually operated presses also are known for producing portions of dough or of similarly soft foodstuff masses, such as e.g. from the DE-2704432 or DE-3809730. In the first mentioned case merely a mechanism is concerned for moving a piston over constant increments in a dough-filled cylinder in such a manner that with each actuation an identical quantity of dough is squeezed out of openings provided at the bottom end of the cylinder: the cylinder thus represents a container from which, just as from a tooth paste tube, a given product quantity is expelled during each actuation of the manually operated lever. The second case represents the old potato press, i.e. a cylinder with openings provided in its bottom via which the hand-operated piston presses a certain quantity of potato mass--so-called "Spatzle"--and the invention merely proposes that the detachable actuating pin of the lever be secured against being lost. Both of these arrangements, in fact just represent manually operated dough presses and can not furnish any teachings concerning the objective of the present invention, which the production of dough disks for pizzas of calibrated volume, and thus of calibrated weight, according to the requirements described above.
Proposed by the applicant of the present invention furthermore a manually operated portioning device for forming balls of pizza dough is known applied for on Jan. 14, 1999 under the Swiss Patent Application number 1999 0057/99.
This application concerns a portioning apparatus suited to produce balls of pizza dough or dough portions of approximately spherical shape and suitable for forming pizza disks using machines which mechanically spread the dough under the influence of centrifugal forces, which corresponds to the objective of the present invention also. According to this proposal the dough is pressed into a cup-shaped container formed by a combination of a cylinder and a piston defining a chamber which in its final position corresponds to the calibrated volume of the dough ball. For obtaining the desired calibration of the volume of the dough ball said chamber is provided with at least one opening via which the excessive quantity of dough can be squeezed out and can be separated from the dough mass remaining inside the chamber.
This manually operated portioning apparatus, however, still shows two disadvantages which can not be neglected, namely:
a) dough balls are produced instead of dough disks. Such balls, if they are to be spread out correctly in the pizza spreader machine under the influence of centrifugal force, thus must be flattened by hand in such a manner that a dough disk of considerable thickness (of about 10 mm or more) is formed which can be considered as an intermediate product in the pizza production process according to the present invention, and PA1 b) The operation of squeezing the excess dough quantity via one or more openings provided in the chamber has proven to require application of considerable physical effort as the dough due to its very tough consistency resists against being squeezed out of one or more openings of a closed chamber. The forces to be applied thus prove excessive and require a very robust construction of the portioning device requiring also considerable space if sufficient multiplication of the forces is to be ensured (length of the lever arm). PA1 a) permitting the production of dough disks of calibrated volume instead of dough balls. The dough disks are better suited as an intermediate product than the dough balls described as they obviously can be spread out into pizza disks of the desired final diameter using the centrifugal force without requiring any additional operations compared to the dough balls which before being spread out under the influence of centrifugal force must be flattened by hand in such a manner that they form a disk. PA1 b) reducing the muscle power to be applied for operation of the machine and thus at reducing also the dimensions required of the machine, and finally also the cost of producing the machine.